J/AJ/133/1027 Positions for 179 Swift X-ray afterglows (Butler+, 2007)
Refined astrometry and positions for 179 Swift X-ray afterglows.
Butler N.R.
<Astron. J., 133, 1027-1033 (2007)>
=2007AJ....133.1027B 2007AJ....133.1027B
ADC_Keywords: Gamma rays ; Positional data
Keywords: gamma rays: bursts - supernovae: general - telescopes -
X-rays: general
Abstract:
We present a refined catalog for the positions of 179 gamma-ray burst
(GRB) X-ray afterglows observed by the X-Ray Telescope (XRT) on Swift
prior to 2006 November 1. The positions are determined by detecting
X-ray field sources in the deep X-ray images and comparing the
centroids to those of optical sources in the Digitized Sky Survey red2
catalog or the Sloan Digital Sky Survey Data Release 5 catalog. Half
of the 90% confidence error region radii are <2.2". The error regions
areas are typically ∼4 times smaller than the best XRT team error
regions, although the positions require deep X-ray integration (>20ks)
and cannot be generated nearly as rapidly after the GRB. The positions
derived for >90% of 77 bursts with optical afterglows are consistent
with the optical transient positions, without the need for systematic
error. About 20% of the afterglow positions require a sizable shift in
the Swift satellite aspect. We discuss the optical/X-ray properties of
the field sources and discuss the implications of the frame offsets
for studies of optically dark GRBs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 43 179 Refined XRT GRB Afterglow Positions
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See also:
X/20 : The Fourth BATSE Burst Revised Catalog (Paciesas+ 1999)
II/282 : The SDSS Photometric Catalog, DR6 (Adelman-McCarthy+, 2007)
J/A+A/455/813 : BeppoSAX catalog of GRB X-ray afterglows (De Pasquale+, 2006)
J/A+A/473/347 : BeppoSAX complete catalogue of GRBs (Vetere+, 2007)
J/A+A/448/L9 : Position catalogue of Swift XRT afterglows (Moretti+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB GRB identification
9- 10 I2 --- n_GRB ? Number in Fig.3 (1)
12- 13 I2 h RAh Hour of Right Ascension (J2000)
15- 16 I2 min RAm Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 34 F4.1 arcsec DEs Arcsecond of Declination (J2000)
36 A1 --- Off [o] Indicates position lying outside the
refined XRT-Team error region
38- 41 F4.1 arcsec Err90 The 90% confidence error region radius
43 A1 --- n_Err90 [ab] Matching optical catalog (2)
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Note (1): Number refers to Figure 3 and denotes a burst with an
optical transient (OT) position.
Note (2): Flag as follows:
a = Position matching with SDSS DR-5 catalog
b = Position matching with DSS-red2 catalog
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 09-Jan-2009